Extreme Pain after surgery

I have just had surgery on my spine L2,3,4,5, and S1, the Doctor is very experienced, and I have a lot of respect for him,however since I've returned home from Hospital about 8 weeks now I have been doing a lot of things that cause extreme pain to the extent that I end up crying. I sweep out our house and mop every morning as well as peel and cut vegitables every morning. Also walking causes pain and I wake up every morning about 3 am in extreme pain and need to take the pain killers that take about an hour to work, I have to endure the pain for the hour or more before they start to work.
I have had screws inserted in my spine and the surgeon also worked on a previous fusion I had back in 1984.( I had L3.4.5. and S1fused then with bone no screws etc.and I had my entire lower body covered in plaster at that time for 3 months.
Is it possible that I have done damage to my latest fusion? I also run a home based business that requires me to take orders, pack the orders line up at the local Post Office and send the orders, which also requires me to move and carry large boxes weighing 20 to 30 k.g.
Should I request another X Ray or Scan to see if I've done any damage? I also take 20 mg and 30 mg OxyContin 2 times a day as well as Codalgin Forte 30+ 500 MG as required which seems to help a little.
Any suggestions would be very welcome.Has any one else experienced the same and have they got any relief?